The present invention relates to improvements in apparatus for manufacturing semi-frozen custard-like desserts, in general, and specifically to improvements in apparatus for manufacturing soft ice cream and the like from prepared liquid mixes.
The improvements described and claimed therein were made to a machine similar to that described in U.S. Pat. No. 4,463,572 and the prior art discussed therein is applicable hereto. However, the improvements described and claimed herein will be applicable to almost any machine for manufacturing soft ice cream, providing suitable modifications were made to adapt the present invention to the specific structures of such machines. Those skilled in the art will recognize that the benefits of the present invention would attach to any machine incorporating it, without detracting from its novelty and usefulness.
Among the problems encountered with existing soft ice cream machines is a tendency for them to "freeze up" when numerous small portions are being served. Many machines turn on the refrigeration compressor and beater when portions of product are served to compensate for the rise in temperature that takes place as new, warmer premix is released from a reservoir into the freezing chamber. Those skilled in the art know that the product nearest to the dispensing spigot will be substantially cooler than that closest to the inlet from the reservoir into the freezing chamber and, if numerous small servings are dispensed, the freezing process will be continuous and the product in the freezing chamber will have a tendency to freeze into a solid mass. When this happens, either the machine must be shut off until this frozen material has softened, or some provision must be made to heat this portion to prevent if from solidifying. If the machine is set to avoid this problem, during periods of infrequent servings the machine will serve ice cream which is insufficiently frozen.
Another problem encountered with existing machines relates to those extended periods when no product is served. Some makers of these machines have incorporated a switch which will place the machine into a standby condition which reduces the amount of mixer agitation during such periods. However, it is easy to forget to operate the switch, either to place it into standby condition, or to place it back into normal condition.
A further problem relates to conditions encountered when serving numerous large portions. Under these conditions, the freezing mechanism may not be able to keep pace with the serving demands and the product begins to exhibit characteristics of inadequate freezing. If the freezing capabilities are set to handle this problem, the machine will freeze up during extended periods of non-use or, conversely, of producing many small servings, as hereinbefore described.
An additional problem of existing machines relates to the tendency of soft ice cream to "age", or become less palatable, during periods of low use. This tendency can be minimized by maintaining the consistency of the mix in one of several ways, e.g., reducing its temperature. However, busy service personnel have little time to enticipate periods of unusual demand and make the required machine adjustments. The preferred embodiment of the present invention specifically addresses this problem and its solution.
These and other problems are solved by the novel improvements herein described and claimed, as will be recognized by those skilled in the art.